Autopilot for your MGL Avionics EFIS

Autopilot ControlThe MGL Avionics EFIS contains a built-in autopilot. All you do is install the servos in the aircraft and the control and AP engage/disengage is handled directly by the EFIS using the keypad, or via a remote switch (and IOX). No other control modules are required.

MGL Avionics have introduced our own stepper motor-based servos, and are still pleased to be working with the Gold Standard Servos made by Trio Avionics.

The EFIS handles all autopilot controls, and you can navigate using GPS track steering, Course steering, with multiple Vertical Modes and many other functions using any of the navigation sources in/connected to your EFIS (internal GPS, external GPS, external nav radio, etc.). For around $2,000 you have a full 2-axis autopilot. Or, if you simply want a roll-axis autopilot (‘wing leveler’), you would be spending about $1,000!

  • Click here to download the MGL Avionics Autopilot Manual (for MGL and Trio Servos)
  • Click here to download the MGL Avionics Servo Manual
  • Click here to purchase Servos and Autopilot Parts

MGL Avionics and Trio Avionics Servo Comparison

MGL Avionics Servo

Servo smaller

Stepper motor based, single stage spur gear
No clutch, minor residual torque if not engaged
CAN and RS232 interface
Can be used with Odyssey, Voyager, Enigma, XTreme
May need COM Extender module for Enigma if serial port used for other purpose
Output shaft can operate over any range and angles
Safety override: Shear screw
Electronically adjustable output torque
Direct motor overdrive
Two moving parts (motor shaft, output shaft)
Contactless position sensing
Capable of measuring actual force acting on output shaft (trim sensing)
Heavier than Trio servo (weighs 1.38Kg/3lbs)
Electrical interface connection: D9 connector
Higher cost compared to the Trio servo
Operates from 12V and 24V (28V) systems
Current requirement approximately 1A average (engaged), 0.6A at 24V

Trio Avionics Servo

Gold Standard Servo

DC motor based, mutiple stage spur gear
Electric clutch, no residual torque if not engaged
RS232 interface
Can be used with Odyssey, Voyager, Enigma
Needs COM Extender module in all cases
Output shaft operates over fixed range and angles
 (arm can be positioned in 90 degree steps)
Safety override: Internal, sacrificial gear
Output torque adjustable mechanically (requires opening of servo)
Slipper clutch on output shaft
Many moving parts
Position sensing using potentiometer
No internal trim sensing
Lighter than MGL servo (weighs 0.8Kg/1.76lbs)
Electrical interface connection: Flyleads to automotive connector
Lower cost than the MGL Servo
12V systems, requires pre-regulator for 24V systems
Current requirement approximately 1A average (engaged)

The above table gives a basic comparison of servo choices for your MGL EFIS. Overall, the servos perform much the same function but small differences may make one of the servos preferable for your installation.

The MGL servos may be of advantage for aircraft with low stability / sensitive controls due to their increased speed and greater position accuracy. The Trio servos perform well in more stable aircraft where absolute accuracy and speed are of less importance.